• Tribology and Lubricants
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• 제27권5호
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• pp.269-274
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• 2011

The purpose of this paper is to study and analyze the improvement method for the failure examples including the vehicle brake system in actual field. It was verified that the indicator plate of pad wear scratched the brake disk because of wearing after displacement of non- identification parts pad. The caliper of other vehicle was installed with brake system verified the phenomenon produced groove in center point because of one side wear when the pad was not fully contacted with the rub disk by other action surface pressure and pad action condition. It verified that the crack phenomenon fatigue was produced by brake thermal deformation because of decreasing the thickness by grinding to modify the non-uniformed wear of brake disk. It verified that the friction sound was produced by the friction phenomenon because of non-uniformed contact of lining and an alien substance with inner of the drum and lining braking by crack phenomenon with brake drum surface.

• 한국인쇄학회지
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• 제22권1호
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• pp.29-38
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• 2004

With increasing interests in environment matters over the world, incessant efforts to develop products which meet these environmental requirements have been made also in paint industry. Among the efforts in this field, UV(Ultra Violet) curing system is focused as one of most potential system. It is because this system not only proved to be environmentally friendly compared with heat curing system or other system but also has economical merit of smaller facility, less energy consumption, and better productivity. Superior properties in many application is surely one of its dominant merit. With these advantage UV system is applied to a variety of industrial fields and expected to have continuous growth in the future. As practical application of UV system has shown lasting progress, R&D on basic material of this system keeps up with. This is a study on photo-initiator that is a fundamental substance in UV curing method and amine, its aid for better effect. After reviewing on them in the aspects of function, economy, and stability, optimal foumula is pursued through experiments when applied to real products.

• Applied Microscopy
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• 제46권1호
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• pp.20-26
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• 2016

Our work on $Sc_2O_3-W$ matrix dispenser cathodes had been reviewed in this paper. The cathode with uniform distribution of $Sc_2O_3$ had been obtained using liquid-liquid doping method. The cathode had excellent emission property, i.e., the emission current density in pulse condition could reach over $35A/cm^2$. It was found that the cathode surface was covered by a Ba-Sc-O active substance multilayer with a thickness of about 100 nm, which was different from the monolayer and semiconducting layer in thickness. Furthermore, the observation results displayed that nanoparticles appeared at the growth steps and the surface of tungsten grains of the fully activated cathode. The calculation result indicated that the nanoparticles could cause the increase of local electric field strengths. We proposed the emission model that both the Ba-Sc-O multilayer and the nanoparticles distributing mainly on the growth steps of the W grains contributed to the emission. The future work on this cathode has been discussed.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.1673-1677
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• 2008

A method of construction with a basis treatment that uses a latticed bamboo mat puts bamboo's peculiarity and bamboo mat's bending substance to use, and a latticed bamboo mat equally distributes to embankment loading in a basis ground. Therefore it prevents ground destruction by an ill-balanced load and an irregular ground subsidence, and it makes safety system. This investigation make progress a soil box model by a dredged reclamation ground of west and south sea at domestic area, and make a comparative study and analyze the strengthening effect based on a grid size of a bamboo-mat and ground failure that it will use in the field.

• 대한예방한의학회지
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• 제18권1호
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• pp.23-41
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• 2014

Objective : The purpose of this study was to lay the groundwork for understanding the details and scope of the legal definition of medicinal products, following the changes in the relevant laws and regulations. This will let readers properly understand the origins of the ongoing conflicts on herbal drugs and new drugs from natural products that are present in the medical field and the medical industry. Possible solutions are proposed in the end. Method : I analyzed the changes in definition of medicinal products since 1945 that have been used in relevant laws and regulations(i.e. Pharmaceutical Affairs Act) and drug approval process(i.e. New Drug Application and Investigational New Drug Application). Results : Legal definition of medicinal products has changed in accordance with the changes in the pharmaceutical industry, such as the establishment of dualistic medical and pharmaceutical System and the introduction of the substance patent. Due to those changes, boundaries of Western medicinal products and health food expanded, while those of herbal medicine products relatively downscaled. Conclusion : Legal definition of medicinal products-i.e. Herbal Drugs, Crude Drugs, and New Drugs from Natural Products-should be reestablished according to academic legitimacy and dualistic medical and pharmaceutical System.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.244-252
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• 2021

Wind plays an important role in cases of unexpected radioactive pollutant dispersion, deciding distribution and concentration of the leaked substance. The accurate prediction of wind has been challenging in numerical weather prediction models, especially near the surface because of the complex interaction between turbulent flow and topographic effect. In this study, we investigated the characteristics of atmospheric dispersion of radioactive material (i.e. ¹³⁷Cs) according to the simulated boundary layer around the HANARO research nuclear reactor in Korea using the Weather Research and Forecasting (WRF)-Mesoscale Model Interface (MMIF)-California Puff (CALPUFF) model system. We examined the impacts of orographic drag on wind field, stability calculation methods, and planetary boundary layer parameterizations on the dispersion of radioactive material under a radioactive leaking scenario. We found that inclusion of the orographic drag effect in the WRF model improved the wind prediction most significantly over the complex terrain area, leading the model system to estimate the radioactive concentration near the reactor more conservatively. We also emphasized the importance of the stability calculation method and employing the skillful boundary layer parameterization to ensure more accurate low atmospheric conditions, in order to simulate more feasible spatial distribution of the radioactive dispersion in leaking scenarios.

• Journal of Magnetics
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• 제16권4호
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• pp.457-460
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• 2011

In this paper, magnetic property and magnetocaloric effect (MCE) in perovskite manganites of the type $La_{(0.75-X)}Ce_XCa_{0.25}MnO_3$ (x = 0.0, 0.2, 0.3 and 0.5) synthesized by using the standard solid state reaction method have been reported. From the magnetic measurements as a function of temperature and applied magnetic field, we have observed that the Curie temperature ($T_C$) of the prepared samples strongly dependent on Ce content and was found to be 255, 213 and 150 K for x = 0.0, 0.2 and 0.3, respectively. A large magnetocaloric effect in vicinity of $T_C$ has been observed with a maximum magnetic entropy change (${\mid}{\Delta}S_M{\mid}_{max}$) of 3.31 and 6.40 J/kgK at 1.5 and 4 T, respectively, for $La_{0.55}Ce_{0.2}Ca_{0.25}MnO_3$. In addition, relative cooling power (RCP) of the sample under the magnetic field variation of 1.5 T reaches 59 J/kg. These results suggest that $La_{0.55}Ce_{0.2}Ca_{0.25}MnO_3$ compound could be a suitable candidate as working substance in magnetic refrigeration at 213 K.

• 한국응용과학기술학회지
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• 제39권2호
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• pp.368-376
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• 2022

자연발화 현상은 산업현장 또는 우리 생활 속 어디에서나 발생하며 물질이 대기 중에서 점화원 없이 스스로 발화되는 현상이다. 화학반응 속도가 빨라져 발생하는 열이 증가하게 되어 자연발화의 위험성은 더욱 커진다. 본 연구에서는 식품과 화장품 소재로 이용되는 안전한 원료를 배합하여 다양한 자연발화 현상 중 특히 석탄 자연발화 방지제를 제조하였다. 인도네시아산 저열량, 저급탄에 대한 Lab과 Field Test를 통하여 석탄 자연발화 억제 효과를 확인하였다. 옥외 현장 테스트 결과, 비교군(90일 후 발화)에 비하여 본 연구에서 제조한 발화방지제는 120일 이상 우수한 자연 발화억제 효과를 나타내었으며 실내저탄장에서 50일 동안의 CO의 농도변화를 비교하여 CO 농도 제어 효과를 확인하였다. 비교군인 석탄, 기존의 발화 방지 방법보다 우수한 결과를 확인하였다. 또한, 환경을 고려한 토양 및 수질 시험, 작업 근로자를 고려한 발화방지제의 MSDS, 수질, 안 자극 등의 공인시험을 통하여 환경과 근로자 작업환경의 안전성 등을 연구하여 2024년부터 적용되는 실내저탄장용 석탄 발화방지제의 가능성을 확인할 수 있었다.

• 지역사회간호학회지
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• 제13권4호
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• pp.595-607
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• 2002

The objectives of this study were to identify the phenomena of school health nursing at schools in Korea and to contribute to building a school health domain of International Classification for Nursing Practice. A retrospective method was used in this study to develop ICNP during the period from July to October 200l. The procedure of the study involved choosing nursing phenomena using preliminary terms from the reports on the field of school health nursing practice documented by nursing students in 10 different nursing colleges. The detail procedures of the study were as follows. 1) Choosing nursing phenomena by using preliminary terms 2) Choosing the characteristics of school health nursing practice from the selected nursing phenomena 3) In order to make a consensus regarding the appropriate characteristics of phenomena. 15 study group members re-categorized the nursing phenomena through 5 times of cyber meetings and 3 times of formal meetings. 4) To verify each characteristic, 5 community nursing faculties and 25 school health nurses participated in the procedure to give scores on nursing characteristics. 5) Classification of the definite nursing phenomena and characteristics. Following the 5 step procedures, school health nursing phenomena were categorized into human and environmental domains. Human domains were classified into human behavioral and functional domains. Environmental domains were classified into physical and psychosocial domains. The essential characteristics of each phenomena were selected when it obtains the mean score of 3.0 or over at the related characteristics. The human behavioral domain consisted of 7 phenomena including risk for spinal disorder, inadequate dietary habit, inadequate weight control, smoking and substance abuse, inadequate stress management, inadequate sex related coping strategies and inadequate accident management. The human functional domain consisted of 6 phenomena including inadequate eye care and visual management, risk for respiratory disorder, inadequate dental health care, inappropriate infectious disease control, risk for gastrointestinal disorder, and lack of sexual identity. The physical environmental domain consisted of 6 phenomena including risk for incident at inside classroom, risk for incident at outside classroom, risk for incident around school, risk for exposure to hazardous facilities around school. inadequate garbage and disposal management, and inadequate physical environment for learning. The psychosocial domain included impaired social interaction at school. Each phenomenon was composed of 2 to 8 characteristics and all phenomena will include a total number of 85 characteristics. The phenomena of school health nursing in Korea partially confirmed school health architecture of ICNP. Further study on verification of school health nursing phenomena in Korea needs to be done to support the findings of this study through review of literature on nursing classifications or field studies.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1162-1162
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• 2001

Whereas NIR spectroscopy has been applied in agriculture for more than 20 years, few studies refer to those plant substances occurring only in smaller amounts. Nevertheless there is a growing interest today to support efficiently activities in the production of high-quality medicinal and spice plants by this fast and non-invasive method. Therefore, it was the aim of this study to develop new NIR methods for the reliable prediction of secondary metabolites found as valuable substances in various plant species. First, sophisticated NIR methods were established to perform fast quality analyses of intact fennel, caraway and dill fruits deriving from single-plants [1]. Later on, a characterization of several leaf drugs and the corresponding fresh material has been successfully performed. In this context robust calibrations have been developed for dried peppermint, rosemary and sage leaves for the determination of their individual essential oil content and composition [2]. A specially adopted NIR method has been developed also for the analysis of carnosic acid in the leaves of numerous rosemary and sage gene bank accessions. Carnosic acid is an antioxidative substance for which several health promoting properties including cancer preservation are assumed. Also some other calibrations have been developed for non-volatile substances such as aspalathin (in unfermented rooibos leaves), catechins (in green tea) and echinacoside (in different Echinacea species) [3]. Some NIR analyses have also been successfully performed on fresh material, too. In spite of the fact that these measurements showed less accuracy in comparison to dried samples, the calibration equations are precise enough to register the individual plant ontogenesis and genetic background. Based on the information received, the farmers and breeders are able to determine the right harvest time (when the valuable components have reached their optimum profile) and to select high-quality genotypes during breeding experiments, respectively. First promising attempts have also been made to introduce mobile diode array spectrometers to collect the spectral data directly on the field or in the individual natural habitats. Since the development of reliable NIRS methods in this special field of application is very time-consuming and needs continuous maintenance of the calibration equations over a longer period, it is convenient to supply the corresponding calibration data to interested user via NIRS network. The present status of all activities, preformed in this context during the last three years, will be presented in detail.